Anuncios

3 Marzo 2004: The March 2004 edition of the Newsletter features news about the Adaptive Optics Development Program, progress reports from the Large Synoptic Survey Telescope and the AURA New Initiatives Office, and information on preparing observing proposals for 2004B.

25 Febrero 2004: A Canadian/Gemini team led by Tim Davidge (Herzberg Institute of Astrophysics) used the ALTAIR adaptive optics system with the Near Infrared Imager (NIRI) on the Frederick C. Gillett Gemini North Telescope to probe the red stellar content in the starburst galaxy M-82. The field studied is at a projected distance of 1 kiloparsec above the disk plane of the galaxy. This amorphous, nearly edge-on galaxy is the third brightest member of a nearby collection of galaxies called the M-81 group which is located about 12 million light-years from our Galaxy. The interactions of galaxies in the M-81 group spur bursts of star formation in its members and M-82 appears to now be experiencing such a violent outburst. This activity in the disk of M-82 appears to drive a bipolar galactic wind that feeds gas to the outer regions of the galaxy. This work indicates that recent star formation in M-82 …

2 Febrero 2004: Wide-field telescope observations from the CTIO Blanco 4-meter telescope of the remote and therefore early Universe, looking back to a time when it was a fifth of its present age (redshift = 2.38), have revealed an enormous string of galaxies about 300 million light-years long. This new structure defies current models of how the Universe evolved, which can’t explain how a string this big could have formed so early.

21 Enero 2004: Trailing 200,000-light-year-long streamers of seething gas, a galaxy that was once like our Milky Way is being shredded as it plunges at 4.5 million miles per hour through the heart of a distant cluster of galaxies. These findings use data from the Mayall 4-meter and Gemini Telescopes.

14 Enero 2004: The mirror for the SOAR 4-meter telescope arrived safely on Cerro Pachón in Chile on the afternoon of 9 January 2004 to the great excitement of the SOAR project team, who will now prepare the optics system for first light. Dedication of the telescope is planned for mid-April.

5 Enero 2004: Why are some galaxies brighter than others? Bright galaxies where stars are forming may outshine dimmer, more massive galaxies. In all previous surveys of the “Redshift Desert,” the brighter star-forming galaxies were the only type bright enough to be sampled. The Gemini Deep Deep Survey (GDDS) was able to sample the dimmer, more massive galaxies and provide a better representation of the galaxies at this epoch of the Universe. The GDDS results revealed that there is a greater abundance of these more massive and older galaxies than expected from current models when the Universe was only 20-40% of its current age.

23 Diciembre 2003: The staff of the National Optical Astronomy Observatory wishes you all the best this holiday season.

9 Diciembre 2003: The Gemini Near-InfraRed Spectrograph, designed and built by NOAO, has been mounted on the Gemini South telescope in Chile. This multi-million dollar, long-slit spectrometer will help astronomers make measurements of the chemical abundances of stars in other galaxies, the conditions at the centers of other galaxies (including very distant young objects) and the initial mass functions for very young star clusters.

3 Diciembre 2003: There are six research assistant positions available for the summer of 2004. As part of their research activities, REU students gain first-hand experience with KPNO’s state-of-the-art telescopes and develop expertise in astronomical data reduction and analysis. Applications are due January 26, 2004.

2 Diciembre 2003: Verne Smith of the University of Texas El Paso led an international team of American, Canadian, Brazilian and Japanese astronomers to a detailed study of the physical properties of the recently discovered nearby brown dwarf companion to Epsilon Indi, the fifth brightest star of the southern hemisphere constellation Indus. This T-dwarf star was discovered at Gemini South by Kevin Volk et al (2003) to be a close optical double consisting of an early T dwarf (Epsilon Indi Ba) and a late T dwarf (Epsilon Indi Bb) separated by 0.6 arcsec - see previous announcement, "Gemini Detects Something "Cool" in Our Neighborhood". With an accurately known distance of 3.626 +/- 0.009 pc, Epsilon Indi Ba and Bb are the nearest known brown dwarfs. High-resolution infrared (IR) spectra were obtained on Epsilon Indi Ba using the Gemini South Telescope and the NOAO PHOENIX spectrometer. The properties of Epsilon Indi Ba were explored …

19 Noviembre 2003: The prototype of the Gemini Science Archive (GSAp), shown in the picture below, was recently released to the astronomical community and the general public. This is a significant event in Gemini's maturation since it adds an end-point to the development sequence of high-level software systems. Now a Gemini user can seamlessly move from the application process via the Phase I Tool (the PIT), to observation definition using the Observing Tool (the OT), to observation execution using the Observatory Control System (the OCS), through data handling and storage (via the DHS), and finally into a permanent data archive (via the GSA). The release of the GSAp is an auspicious event and marks the first availability of Gemini science data to not just a project's principal investigator (PI) but to anyone who wants to make use of it. Many ground-based observatories and all space-based telescopes have previously developed data archives (for example, …

5 Noviembre 2003: The remnants of a Type 1a Supernova that first appeared in 1572, as imaged by Kitt Peak Visitors Center telescope as part of the Advanced Observing Program.

4 Noviembre 2003: November 4, 2003 A group of astronomers has recently studied the chemical make-up of distant galaxies in the "redshift desert," which is a virtually unexplored region of space between eight billion and ten billion light years away. Because the light from these galaxies moves at a finite speed, the galaxies are being seen when the Universe was between 20% and 40% of its present age. Studying the properties of galaxies at this particular time is important because it corresponds to a special age in the history of the Universe - a time during which it is thought to have made most of its stars. These observations were undertaken using the Gemini North telescope and a uniquely capable instrument, the Gemini Multi-Object Spectrograph (GMOS), which is able to target extraordinarily faint galaxies using a newly developed technique known as "nod and shuffle." This work is reported in "The Gemini Deep Deep …

29 Octubre 2003: ...Is a message that the StarTeachers successfully delivered to thousands of students in Chile and Hawai`i. The second-half of the inspiring StarTeachers program began on Saturday, October 11, in Waikoloa, Hawai`i, with a welcoming gala. During the gala, Gemini was honored to receive the Gabriela Mistral Medal for excellence in education from the Chilean Ministry of Education. The gala event kicked-off two weeks of teaching and cultural exchange. The StarTeachers have been busy on the Big Island. More images are provided in the StarTeacher's Photo Album. Additional information about the individual teachers and background information on the StarTeachers program is also available at our website. The StarTeachers spent most of their time in schools and classrooms in East Hawaii infusing students and other educators with their love of science, astronomy and culture. They visited 9 schools total with focused efforts at the Hawaiian StarTeachers' home schools - Keaau High School, …

24 Octubre 2003: NOAO has completed construction and testing of the Gemini Near Infrared Spectrograph (GNIRS). The instrument left Tucson on October 24 on its way to be mounted on the Gemini South telescope on Cerro Pachón in Chile, where it arrived on October 27 (see bottom image). This multi-million dollar, long-slit spectrometer will help astronomers make measurements of the chemical abundances of stars in other galaxies, the conditions at the centers of other galaxies (including very distant young objects) and the initial mass functions for very young star clusters.

22 Octubre 2003: The Gemini Observatory recently reached an important milestone - successful coating of the secondary mirror on Gemini South with silver. Previously, with aluminum coatings on both primary and secondary mirrors, Gemini's combined emissivity was 3.8%. Reaching this new milestone, we are increasingly confident that achieving our ambitious goal of 2% total telescope emissivity is attainable. Reflectivity and emissivity are two measures of a mirror's performance. A highly reflective mirror is desirable in any optical telescope in order to maximize the amount of light reaching the science instrument. Ideally, a coating should reflect as close to 100% of the light that strikes it. In the thermal infrared region of the spectrum, however, a mirror coating emits a great deal of infrared radiation, and the statistical "noisiness" of this emission reduces an infrared instrument's sensitivity to emission from astronomical sources. The emissivity of an optical surface is defined as the ratio between …

6 Octubre 2003: This image of the clouds of gas and dust next to the “neck” and “body” of the Pelican Nebula was produced by an NOAO Survey Program known as the Deep Imaging Survey of Nearby Star-Forming Clouds, led by John Bally of the University of Colorado and Bo Reipurth of the University of Hawaii.

2 Octubre 2003: Daniel Stern of the Jet Propulsion Laboratory and his USA-UK-Chile team of astronomers (including Gemini-South Astronomer Michael Ledlow) used the visiting instrument FLAMINGOS, a multi-object near infrared spectrograph at Gemini South to study the high redshift quasar SDSS J083643.85+005453.3 (SDSS J0836+0054). SDSS refers to the Sloan Digital Sky Survey, where the quasar was first discovered. The authors report their findings in "Gemini-South+FLAMINGOS Demonstration Science: Near-Infrared Spectroscopy of the z = 5.77 Quasar SDSS J083643.85+005453.3", The Astrophysical Journal Letters, 10 October 2003. Both CIV (at 1549 Angstroms) and CIII] (1909 Angstroms) were detected in the quasar at a redshift of z = 5.774 +/- 0.003 (See Figure 2). The new redshift derived from these lines is more accurate than the previous optical estimate (z=5.82), based on a single broad line, Lyman alpha (See Figure 1). Because of its high redshift and foreground absorption by our own galaxy, the quasar is invisible …

30 Septiembre 2003: While searching for planet-sized bodies that might accompany the nearby star system Epsilon Indi, astronomers using the Gemini South telescope in Chile made a related but unexpected detection. The nearest known specimen of a brown dwarf, Epsilon Indi B (now Ba), has a cooler and less massive companion: Epsilon Indi Bb. This discovery was made with the NOAO-built PHOENIX high-resolution spectrometer, using a narrow-band filter within the J-band, and without the aid of adaptive optics. The separation between Epsilon Indi Ba and Bb is 0.7 arcsecond.

25 Septiembre 2003: This nebula, also known as M20, gets its distinct look from dust lanes that seem to divide the nebula into three parts. Its distance is estimated at approximately 5,000 light-years and it can be found in the constellation Sagittarius. This image was taken at the Kitt Peak Visitor Center 20" telescope as part of the Advanced Observing Program.